Quality Inspection of Thick-Walled Steel Plate Coils

In addition to complying with clause 4.2.1, the quality inspection of steel coil pipes should also meet the following requirements:

When the diameter of the coil pipe exceeds 600mm, two longitudinal seams are permitted, with a spacing between the seams greater than 300mm.

(2) The spacing between the two longitudinal seams should be greater than 100mm. The distance from the outer wall of the branch pipe to the longitudinal and circumferential seams should not be less than 50mm.

(3) The circumference deviation and ellipticity of the coiled tubing should comply with the specifications of the design document or manufacturing standards.

(4) The deviation between the end face of the coil and the centerline should not exceed 1% of the outer diameter of the tube, and should not exceed 3mm. The straightness deviation should not exceed 1mm/m.

During the tube coiling process, the surface of the material used should be free from mechanical damage. Areas with severe scratches should be ground and made smooth. The depth of the grinding should not exceed 10% of the board thickness.

All welds on the coiled pipes must pass the penetration test. The appearance inspection of the welds should be carried out in accordance with the welding inspection regulations. After the钢管 has been processed, a leakage test should be conducted as per the specifications.

Welding Material Inspection for Thick-Walled Seamless Steel Tubes

The project team must inspect the quality certificates of the welding materials used by the construction contractor. The quality of welding rods and wires must meet or exceed the current national standards, and comply with the specifications of the welding process evaluation approved by the project team or the design. The inspection personnel of the project team should make detailed records.

(2) The design unit should provide welding performance data for the new materials selected for the design.

(3) The flux coating of the welding rod must not have any detachment or obvious cracks. Welding rods with a production date exceeding one year should undergo a welding rod welding process performance test before use, and only those that pass the test are permitted to be utilized.

(4) The project team must inspect the storage location of welding materials at the construction site, as well as the drying and degreasing facilities, i.e., the second-level welding rod warehouse. It should comply with the current national standard "Regulations for Welding Rod Quality Management" 3223. The contractor should establish a system for the storage, drying, cleaning, and distribution of welding materials. The project team is to conduct inspections, confirm compliance, and maintain inspection records.